Portable video recorder system

ABSTRACT

The invention relates to a portable video recorder system.  
     This system comprises a video shooting part ( 10 ) including an image capturing device ( 12 ), video compression means ( 14 ), a buffer memory ( 16 ) filled by the output of the video compression means and low data rate wireless transmission equipment ( 18, 19 ) having a short range, and  
     a recording part ( 20 ) including a reception equipment ( 22, 24 ) and a cassette, or tape, or disk, or solid state memory recording unit ( 28 ).  
     Preferably means are provided for the simultaneous wireless transmission of data from the memory of the capturing device and the filling of this memory.

[0001] The invention relates to a portable video recorder system.

[0002] The camcorders which are presently available on the market mayhave a very small weight. They may also operate automatically.Therefore, they are quite easy to use. However, it is necessary to useboth hands for controlling the operation of the camcorder. This may beinconvenient for certain usages of a camcorder, for instance if the userwishes to take written notes when he is shooting a scene.

[0003] It is the reason why it has been proposed to separate the imagecapturing part of the camcorder from the processing and recording part.In fact, the mechanical recording part has the greatest consumption ofenergy and it is the heaviest part of the camcorder. In this case, thefirst part, which comprises the image capturing device and a buffermemory, is very light and may be carried with free hands, for instanceon the forehead. The buffer memory may be used, after the shooting, totransfer the recording to a cassette or tape having a greater capacitythan this buffer memory.

[0004] However, a buffer memory has a limited capacity, for instanceabout one minute of recording. Therefore, it is necessary to frequentlytransfer the content of the memory to the cassette. This operation isnot quite convenient. Moreover, during this transfer the image capturingdevice cannot be used.

[0005] The invention overcomes these drawbacks.

[0006] The portable video recording system according to the invention ischaracterized by the fact that it comprises:

[0007] a video shooting part including an image capturing device, videocompression means, a buffer memory filled by the output of the videocompression means and low data rate wireless transmission equipmenthaving a short range, and

[0008] a recording part including a reception equipment and a cassetteor tape or disk or solid state recording unit.

[0009] Of course, audio data, compressed or not, are generallytransmitted together with compressed video data.

[0010] With a wireless transmission the user may carry the recordingpart in the pocket or in a bag.

[0011] Preferably, the system comprises means for simultaneouslytransmitting data from the memory of the capturing device and fillingthis memory. Therefore, the transmission and the recording on acassette, tape, disk or solid state memory happen during the shooting ofscenes by the image capturing device.

[0012] In an embodiment the recording part includes a buffer memorywhich provides data to the cassette, tape, disk, or solid state memoryat a higher rate than the wireless transmission data.

[0013] With the provision of two buffer memories, it is possible to useconventional cassette or disk recording units and to transmit the datawith a very low data rate compared to the data rate of filling the firstmemory. Therefore, the transmission means may by very cheap. Forinstance, they may be of the kind which is currently available fortransmitting data from a mobile telephone to a loudspeaker or from amicrophone to a mobile telephone.

[0014] As the buffer memory of the video shooting part is filled at ahigher rate than it is emptied by transmission to the recording part,this buffer memory may be quickly saturated, for instance after oneminute of shooting. This means that the video recording system must beused only intermittently, i.e. after one minute of shooting it isnecessary to wait a few minutes in order that space becomes available inthe buffer memory. This intermittent operation of the system is not adrawback because it corresponds to the usual way of operating acamcorder. The recording time of scenes is generally comprised between10 seconds and a maximum of one minute, and the time separating theshooting of two scenes may be several minutes.

[0015] In brief the invention concerns a portable video recorder systemcomprising:

[0016] a video shooting part including an image capturing device, videocompression means, a buffer memory filled by the output of the videocompression means and low data rate wireless transmission equipmenthaving a short range, and

[0017] a recording part including a reception equipment and a cassette,or tape, or disk, or solid state memory recording unit.

[0018] The portable video recorder system comprises, in a preferredembodiment, means for the simultaneous wireless transmission of datafrom the memory of the capturing device and the filling of this memory.

[0019] The low data rate transmission equipment of the video shootingpart has, in an embodiment, a transmission rate which is about 10 timesless than the data rate of filling of the buffer memory of this videoshooting part.

[0020] The recording part includes preferably a buffer memory whichprovides data to the cassette, or tape, or disk, or solid state memoryat a higher rate than the wireless transmission data.

[0021] The data rate of the wireless transmission equipment may be about2 Megabits per second.

[0022] The portable video recorder system comprises preferably means foraudio detection and storing into the buffer memory of the shooting partand for transmission together with video data.

[0023] Other features and advantages of the invention will appear withthe description of certain of its embodiments, this description beingmade with reference to the herein appended drawing which represents avideo recording system according to the invention.

[0024] The video recorder system represented on the drawing comprisestwo parts:

[0025] A first part 10 for audio and video shooting and a second part 20for audio and video cassette recording.

[0026] The first part 10 is designed to have a very small weight inorder to be carried preferably on the forehead. This first part 10comprises a classical image capturing device 12 with a lens and amicrophone (not shown). The image is detected by CCD detectors. Videoand audio compression means 14 receive the audio and TV data andcompress them, for instance according to the MPEG 2 or MPEG 4 standard.

[0027] The audio and video compressed data are provided to a buffermemory 16 having, for instance, a capacity of 1 Gigabit, and the data ofthis buffer memory 16 are provided to a communication interface 18 inorder to transmit these data with a low data rate through a transmissionantenna 19. The transmission equipment has a small range in order toavoid interferences with neighbouring equipments.

[0028] In an example, the memory 16 is filled at a rate of about 22Megabits/second and the transmission rate of the antenna 18 is 2Megabits/second.

[0029] The data transmitted by antenna 19 are received by receivingantenna 22 which provides, through an interface 24, the received data toa buffer memory 26 and this buffer memory 26 provides the receivedcompressed audio and video data to a cassette recorder 28. In theexample, this recording part 20 is also provided with a LCD display 30.

[0030] The battery (not shown) for controlling the operation of thecapturing part 10 may be very small. This capturing part 10 may have acompletely automatic operation. For the shooting of scenes in anembodiment use is made of a conventional eye controller which detectsthe direction of observation of the eye in order to focus the objectivelens to the scene in the direction observed by the eye of the user.

[0031] As, in the example, the buffer memory has a capacity of 1 Gigabitand is filled at a rate of about 22 Mbits/second, it is filled(saturated) after about one minute of shooting because the transmissionrate of 2 Mbits/second, i.e. the evacuation rate from the memory 16, isnot sufficient to empty the memory. About 10 minutes are necessary fortransmitting the whole content of memory 16 to memory 26. It has beenfound that this necessary intermittent operation of the system is quiteacceptable for such video recorder system because, in general, scenesare shooted intermittently.

[0032] In other words, the invention is based on a deliberate choice ofa low transmission rate, in order to provide a portable video recordersystem at low price and it has been observed that this low data ratetransmission is compatible with the common use of such a product.

[0033] Instead of a cassette recorder, any type of recording unit may beused, such as IC memory recorder or disk recorder including optical ormagnetic recording, for instance a hard disk recorder.

1. A portable video recorder system comprising: a video shooting part(10) including an image capturing device (12), video compression means(14), a buffer memory (16) filled by the output of the video compressionmeans and low data rate wireless transmission equipment (18, 19) havinga short range, and a recording part (20) including a reception equipment(22, 24) and a cassette, or tape, or disk, or solid state memoryrecording unit (28).
 2. A portable video recorder system according toclaim 1 comprising means for the simultaneous wireless transmission ofdata from the memory of the capturing device and the filling of thismemory.
 3. A portable video recorder system according to claim 1 or 2wherein the low data rate transmission equipment of the video shootingpart (10) has a transmission rate which is about 10 times less than thedata rate of filling of the buffer memory (16) of this video shootingpart.
 4. A portable video recorder system according to claim 1, 2, or 3wherein the recording part (20) includes a buffer memory (26) whichprovides data to the cassette, or tape, or disk, or solid state memoryat a higher rate than the wireless transmission data.
 5. A portablevideo recorder system according to any of the previous claims whereinthe data rate of the wireless transmission equipment is about 2 Megabitsper second.
 6. A portable video recorder system according to any of theprevious claims comprising means for audio detection and storing intothe buffer memory of the shooting part and for transmission togetherwith video data.